Height control for molten metal in mold riser



w. G. DRESSEL 3,353,586

HEIGHT CONTROL FOR MOLTEN METAL IN MOLD RISER Nov. 21, 1967 Filed April14, 1965 5 Sheets-Sheet 1 llVVE/VTOR. v W/LL/AM a. DRESS/5L WITNE$ jaw 7Nov. 21, 1967 w. e. DRESSEL HEIGHT CONTROL FOR MOLTEN METAL- IN MOLDRISER Filed April 14, 1965 5 Sheets-Sheet 5 WILL/AM GDRESSEL WITNESSNov. 21, 1967 w. s. DRESSEL HEIGHT CONTROL FOR MOLTEN METAL IN MOLDRISER 5 Sheets-Sheet 4 Filed April 14, 1965 .Lu R Y W m H V w 0/ Z W MML Y//. L B W W/T/VESS '1) A w/a 4 United States Patent 3,353,586 HEIGHTCONTROL FOR MOLTEN METAL IN MOLD RISER William G. Dressel, Elk GroveVillage, IlL, assignor to Amsted Industries Incorporated, Chicago, Ill.,a corporation of New Jersey Filed Apr. 14, 1965, Ser. No. 448,017 11Claims. (Cl. 164156) ABSTRACT OF THE DISCLOSURE A gauging and sensingdevice is used to terminate the fiow of molten metal into successivemolds of varying heights. The gauging device is a vertically movable rodthat contacts an external surface of the mold after the mold has beenmoved into pouring position. The external surface mentioned is fixedrelative to the casting cavity of the mold in order that molds ofvarying heights may be accommodated. The sensing device moves down withthe gauging device and into a riser opening of the mold, serving toterminate the pouring operation upon contact with the rising level ofmolten metal.

The present invention relates to mold riser height control apparatus foruse in conjunction with casting operations.

In casting operations, molten metal is poured into the casting cavity ofa mold. The mold is normally provided To insure that there be sufficientmetal in the riser holes to compensate for the shrinkage in the cavity,the operator often fills the mold and riser holes to a greater extentthan is necessary to accommodate shrinkage. This results in theinefficient and expensive pouring of excess metal.

It has been found difiicult, if not impossible, to accuratelyconditioning mold parts after repeated casting operations.

An object of this invention is to provide apparatus for gauging andsensing the height of molten metal in such riser holes, in order toterminate and otherwise control:

the casting operation.

Other objects and advantages of the invention will appear from thefollowing detailed description taken in conjunction with theaccompanying drawings in which:

FIGURE 1 is a semi-diagrammatic view of a conveyor 1 arrangement fortransporting molds to a pouring station, and of the crane means formanipulating the molds;

FIGURE 2 is a semi-diagrammatic view taken at line 22 of FIGURE 1;

FIGURE 3 is a large scale view of the apparatus of the present inventionmounted on a crane for manipulating the molds, this view beingorientated similarly to FIGURE 1;

FIGURE 4 is a view from the left of FIGURE 3; FIGURE 5 is a diagrammaticview showing the con- 3,353,586 Patented Nov. 21, 1967 veyor means witha plurality of molds thereon, emphasizing the differences of sizes insuccessive molds;

FIGURE 6 is a view similar to FIGURE 3 showing a second embodiment ofthe invention;

FIGURE 7 is a diagram of the hydraulic arrangement utilized in theembodiment of FIGURE 6; and

FIGURE 8 is a diagram of the electrical arrangement utilized in theembodiment of FIGURE 6.

Referring now to the drawings, FIGURES 1 and 2 show diagrammatically aconveyor arrangement for conveying the molds to a pouring station, andfrom that station therebeyond. The molds indicated at 10 are shownresting on and being conveyed by a conveyor 11 of known kind. In theillustration shown, the molds are conveyed to the right, and as eachmold reaches the position shown at 10a the conveyor 11 stops and a crane12 lifts the molds successively into pouring position indicated at 10b,and then out of that position and again onto the conveyor where they areconveyed away from the pouring station. The crane 12, of known kind, ismoved along an overhead track 14 between the full-line and dotted-linepositions. The crane includes an A frame 16 and a B frame 18 extendingdownwardly into proximity with the conveyor 11, and utilized for liftingthe molds into and out of the pouring position. Each, the A frame andthe B frame, is made up of two legs such as 16a and 16b in FIGURE 2,which straddle the molds. In the operation of the crane, and assumingfirst the full-line position of FIGURE 1, the A frame 16 grips the moldat the position 10b, while at the same time the B frame 18 grips themold at the position 10a, and the crane is then moved along the overheadtrack to the dotted-line position where the mold 10b is deposited on theconveyor 12 and the mold 10a is deposited at the pouring position forthe filling operation.

The pouring station includes a pit 22 in which a ladle 24 is deposited.Compressed air is introduced into the ladle 24, which is at that timesealed, through a conduit 26 by known means. Upon consequent increase inpressure the molten metal in the ladle is forced up through the pouringtube 28 into the mold 10b, which is placed in pouring engagement withthe pouring tube, as shown more clearly in FIGURE 3. Although suchpressure pouring type of casting is here disclosed, the invention is notlimited thereto but is applicable to other types, such as gravitypouring.

As best shown in FIGURES 3 and 4, the mold 10 is designed for castingrailway car Wheels, and as such includes a cavity 30 shaped for thatpurpose, but it will be understood that the invention is not limited tosuch cast article. The mold 10 is a chill mold and includes graphitedrag and cope sections, 32 and 34 respectively, which together definethe casting cavity 30. The drag section 36 is held between a bottomsteel member 40 and a top steel member 42 having a flange 44. The topgraphite section 38 is held between a top steel member 46 and a bottomsteel member 48 which includes a flange 50.

The casting cavity 30 is preferably formed in both mold sections, i.e.,an upper portion 30a is formed in the underface 52 of the cope section38, and another portion 30b is formed in the upperface 54 of the bottomor drag section 36. In the course of casting, it becomes necessary oradvisable to recondition the graphite sections of the mold, due todeterioration by the molten metal. This is done by separating the moldand exposing the faces 52 and 54 of the sections thereof, and performingthe reconditioning or resurfacing operations on those faces. Thisoperation reduces the depth dimension of those sections which may varybetween, for example, 21 in .a new mold to about 14" or less after anumber of reconditioning operations. After such reconditioningoperations, the graphite sections are then incorporated again in thesteel members and the latter clamped together. The bottom steel member48 is applied to the bottom surface of the cope section 38 while the topsteel member 42 of the drag is applied to the drag section 36, and thetwo sections of the mold fitted together again. These steel members 42and 48 again assume the same position relative to the respective faces54 and 52, and thereby are again in the same position relative to thecavity 30 regardless of the depth dimensions of the graphite sections 36and 38. However, due to the reduction in depth dimensions of thegraphite sections, the two steel members of each part of the mold willbe closer together, that is, the steel members 40 and 42 will be closertogether, and the same is true with respect to the steel sections 46 and48. While the overall height or depth of the mold is reduced after eachconditioning operation, the relation between the flanges 44 and 50, andthe cavity, remains the same as noted above. This phenomenon will bereferred to again hereinbelow, with respect to the sensing operation.

The cope section 38 is provided with at least one, and preferably aplurality of, riser holes 56 communicating with and rising from thecavity. Each riser hole is provided with a liner S8, of sand or sandmix, having an undersurface 58a shaped according to the adjacent portionof the article to be cast. A relatively small aperture 60 is providedfor allowing the molten metal to rise into the riser hole and recedeinto the cavity. The liner 58 and the method of placing it into positionare known.

The A frame 16 is shown in FIGURES 3 and 4, having a foot 62 on each leg16a and 16b, the two feet gripping under the flange 64 of the bottomsteel member 40 of the mold, in the operation of picking up the mold andsetting it down.

The sensing apparatus, in the first embodiment of the invention, isindicated in its entirety at 66, and includes a carriage 68 mounted forvertical reciprocation on a channel support 80. The upper and lower endsof .channel support 80 are secured to one of the legs, such as leg 16aof the A frame 16, by respective brackets 82 and 84. In order tofacilitate the flow of gases from the casting cavity, the mold is tiltedduring the pouring operation and the sensing apparatus 66 is preferablydisposed at a slight angle, on the order of 3 /2" from the vertical.

Additional brackets 86 and 8 8 are secured to the upper and lower endsof the channel support 80, and a guide rod 90 is secured between saidbrackets for guiding the movements of the carriage .68. The carriage .68includes a head piece 92 having an aperture for receiving the guide 90.The head piece 92 is .part of a frame indicated in its entirety at 94,which also includes a foot 96 having an aperture receiving the guide 90.Interconnecting the head 92 and foot 96 is a rod 98, and the carriage 68head 92, rod 98 and foot 96 form a rigid and unitary assembly slideablevertically as guided by the rod 90. The sliding movements of thisunitary assembly are ,provided by a power device 100 which may bepneumatically operated and which includes a cylinder 102 and a doubleacting piston 104 having connecting rods 10.6 and 108 respectively,connected to opposite sides thereof. The upper connecting rod 106 isconnected to the head 92, while the lower connecting rod 108 isconnected to the foot 96. Upon introduction of compressed air on oneside or the other of the piston, the assembly 94 is moved up or downmoving the carriage 68 with it.

The carriage 68 secured to the head member 92 of the frame 94 includes ahorizontal arm 110 on which is mounted a sensing element 112 which, inthe present instance, is in the form of a bob sufficiently light tofloat on molten steel. This. 12G p efe y of g p or other suitablematerial, is secured to the lower end of a chain 114 for the most partencased in a protective tube 116 attached to the arm 110. The upper endof the chain is supported on one end of a lever arm 118 fulcrumed at120, the other end having an element 122 operative for engaging andoperating a switch 124. The bob 112 normally is sufficiently heavy tomove the arm 118 in counterclockwise direction for holding the righthand end up to a first position, and upon the bob being raised by themolten metal, the arm swings in the opposite direction with consequentcontrol of the switch 124. If desired, a counterweight 126 may bemounted on the right hand end of the arm for assuring movement thereofwhen the bob is raised. Also, the chain 114 may be provided withadjustment means 128 for adjusting the length thereof.

The foot 96 has an extension 130 which is provided for engaging one ofthe elements of the mold in the sensing operation, which is preferablythe flange 44, which is one of those which always assumes the sameposition in the mold relative to the cavity, regardless of the size ofthe mold parts which are altered by resurfacing, as referred to above.Other flanges above the flange 44 may have notches therein for enablingpassage of the extension 130 therepast.

After the mold is placed in pouring engagement with the ladle (FIGURES 1and 3) as described above, com pressed air is introduced into thecylinder 102 above the piston 104, in order to lower the carriage 68 andproject the bob 112 into the riser hold 58. The carriage 68 and bob 112are lowered until the foot extension 130 of the frame 94 engages theflange 44 on the drag section 32 of the mold, as shown in FIGURE 3. Theflange 44 thus serves as a means for limiting movement of the carriage68, and in this position the bob 112 is at the desired height in theriser hold 56 for performing the intended sensing operation, the lengthof the chain, of course, being predetermined to that end. As the moltenmetal flows up into the cavity 30 and then into the riser hole, itengages the bob 112 at a level represented by the dotdash line 131(FIGURE 3), the relatively rapid movement of the molten metal adding acomponent of force to the flotation of the bob to raise it. When the bobis thus raised, the arm 118 (FIGURE 4) rocks in clockwise direction, andthe switch 124 is actuated as stated above. This switching operation isthen utilized for the desired functions, a principal one of which isstopping the pouring operation. The number of functions controlled bythis switching operation may be as desired, in accordance with theintended degree of automatic control, such as introducing compressed airunder the piston, and opening the upper end of the cylinder and raisingthe carriage .68, as well as other functions such as moving the crane 12for continuing the overall conveying movements of the molds andsuccessive filling operations.

FIGURE 5 illustrates three similar molds, 10c, 10d and 10a, in which thegraphite sections 36 and 38 have been reconditioned and varied indimensions to different degrees. The graphite sections in these moldsare in the three cases different from each other, but the flange 44 ineach case is at the same height relative to the cavity therein so thatupon the extension 130 engaging that flange, the sensing bob 112 isdisposed at the same level in the riser hole relative to the cavity,regardless of the overall height or depth of the molds. The externalsteel members of the three molds are identical.

When a plurality of riser holes 56 are provided, the sensing step may beprovided in any of the holes as desired, the carriage 68 beingpositioned relative thereto for that purpose. In the present instance, ariser hole at a lower portion of the mold is utilized, but the sensingstep may be performed at the intended level by adjusting the height ofthe bob according to which of the riser holes is utilized.

While the foregoing embodiment of the invention utilizes a mechanicalarrangement responsive to movement of the rising molten metal, theinvention is not limited to such arrangement, as stated above andattention is now directed to FIGURES 6, 7 and 8 showing an arrangementin which an electrical circuit is utilized to control the level ofmolten metal. In FIGURE 6 the A frame 16 is shown on which is mounted ahydraulic power device 140 including a cylinder 142 and a ram 144. Thepower device 140 may be of suitable known construction in which the ram144 includes a piston 146 operable in the cylinder and a rod 148extending upwardly, for example, where it is connected with tensionsprings 150 which are also connected with a fixed element of theapparatus. As best shown in FIGURE 7, extending in the oppositedirection from the piston is a rod 152 forming a prod having a terminalelement 154 which may be of stainless steel, and adapted to engage themolten metal in the riser cavity. The power device 140, including allparts thereof, is electrically insulated from the frame 16 and otherconductive parts of the apparatus, for elfective inclusion in anelectrical circuit described hereinbelow. Above the piston 146 is achamber 156 having oil therein in a hydraulic circuit also referred tohereinbelow.

Also mounted on the frame 16 is another hydraulic power device 158(FIGURE 7) having a cylinder 160 and a ram 162 connected with a piston164. The ram 162 extends downwardly out of the cylinder for engagementwith an element of the mold for forming a sensing and limiting means ofthe general kind described above. Below the piston 164 is a chamber 166having a quantity of oil therein, this chamber being connected through ahydraulic line 168 with the chamber 156 in the power device 140, thehydraulic line including a flexible element 170, if desired, forconvenience in mounting the apparatus.

Below the piston 146 in the power device 140 is a chamber 172 into whichcompressed air is introduced. Leading from this chamber 172 is apneumatic line 174 having a flexible element 176 which, as controlled bya valve 178, communicates with another pneumatic line 180 which in turncommunicates with the chamber 182 above the piston in the cylinder 160.Another pneumatic line 184 communicates with a suitable source ofcompressed air (not shown) and leads to the valve 178 and under controlof that valve communicates selectively with the chambers 172 and 182,the compressed air being operative for actuating the pistons asdescribed below.

As shown in FIGURES 7 and 7, the valve 178 is controlled by a solenoid190 and is connected through a conductor 192 with the prod 152. Anotherconductor 194 leads from the mold through a source of potential 196 toanother conductor 198 leading to the solenoid 190. The solenoid 190 isoperative for controlling a set of instrumentalities indicated in itsentirety at 200 which may include, as indicated, valves, switches,relays, etc., the valves including the valve 178 identified above.

In the use of the apparatus of FIGURES 6 to 8, with the A frame 16 inthe proper position relative to the mold being filled, compressed air isintroduced through the line 184, valve 178 and line 180 to the pneumaticchamber 182 of the cylinder 160. This forces the ram 162 downwardlyuntil it engages the intended element such as the flange 44, asdescribed above. This downward movement of the ram displaces the oilfrom the chamber 166 through the line 168 into the chamber 156 andcorrespondingly moves the piston 146 downwardly. The latter movementmoves the prod 152 downwardly into the riser hole of the mold to theposition as determined by the extent of movement of the ram 162, andreaches its lowermost position upon the ram engaging the flange 44.After the members reach this position, the pouring operation isperformed until the molten metal reaches the level as indicated at 132in FIGURE 8, when it engages the prod 152. This closes the circuit ofFIG- URE 8 and energizes the solenoid which in turn actuates the set ofcontrol instrumentalities 200. These instrumentalities control variousoperations including the pouring operation, for example, and actuate thevalve 178 which reverses the flow of compressed air and raises thepiston 146 which, of course, raises the ram 162. It will be understoodthat all of the components and elements involved in the electricalcircuit of FIGURE 8 which include all portions of the power device 140,are electrically insulated from all other parts of the apparatus wherebythe circuit of FIGURE 8 is energized by the prod 152.

While I have hereinto disclosed a preferred form of the invention, itwill be understood that changes may be made therein Within the scope ofthe appended claims.

I claim:

1. Apparatus for use in conjunction with the casting of molten metal ina casting operation utilizing at least one mold having openings therein,comprising gauging means for gauging an external element of the mold,sensing means connected with said gauging means and movable into atleast one of the openings of said mold, means for movement of saidsensing and gauging means in generally vertical directions, said gaugingmeans being movable to said external element to limit the extent towhich said sensing means enters into said opening, and means operativefor controlling said casting operation upon contact of molten metal withsaid sensing means.

2. The invention set out in claim 1 wherein said sensing means includesa bob of less density than the molten metal and said last-mentionedmeans includes a switch operatively connected to said bob.

3. The invention set out in claim 2 in which the bob is secured by afilament, to one end of a fulcrumed lever and means is mounted on theother end of the lever for actuating said switch in response to rockingmovement of the lever pursuant to raising movement of the bob.

4. The invention set out in claim 3 wherein a protective tube isprovided around said filament, said filament being slidable in saidtube.

5. The invention set out in claim 1, wherein a carriage is provided forconnecting said gauging and said sensing means, and wherein a powercylinder is provided for raising and lowering said carriage, said powercylinder comprising a cylinder fixedly mounted relative to saidcarriage, a piston operable in the cylinder, and a connecting rodextending out of each end of the cylinder and connected with upper andlower portions of said carriage, whereby said power cylinder isoperative for raising and lowering the carriage.

6. The invention set out in claim 1 wherein the mold is inclined at anangle and wherein said sensing means is movable along a path inclined ata similar angle.

7. The invention set out in claim 1 wherein said sensing means includesan electrical circuit controlled by the molten metal rising to saidpredetermined level.

8. The invention set out in claim 7 wherein the sensing means includes aprod which enters into said opening and is engaged by the molten metal,and control means is provided which includes an electrical circuitincluding said prod, the mold and the molten metal in series relatlon.

9. The invention set out in claim 7 in which the gauging means isactuated by fluid flow, and the gauging means in turn operates throughfluid flow for mounting the sensing means.

10. The invention set out in claim 9 in which the gauging means islowered by compressed gas, and movement of the gauging means operatesthrough liquid flow for correspondingly moving sensing means, andcompressed gas is utilized for raising the sensing means which in turn,acting through the liquid flow, raises the gauging means.

11. The invention set out in claim 10 wherein the ganging means andsensing means both have a normal elevated position and spring means isconnected to the sensing means for biasing the sensing means and thegauging means upwardly.

References Cited UNITED STATES PATENTS 8 Edstrand 222-16 Sukava 164156Naifziger 164-155 Sukava 164-156 J. SPENCER OVERHOLSER, PrimaryExaminer.

R. D. BALDWIN, Examiner.

1. APPARATUS FOR USE IN CONJUNCTION WITH THE CASTING OF MOLTEN METAL INA CASTING OPERATION UTILIZING AT LEAST ONE MOLD HAVING OPENINGS THEREIN,COMPRISING GAUGING MEANS FOR GAUGING AN EXTERNAL ELEMENT OF THE MOLD,SENSING MEANS CONNECTED WITH SAID GAUGING MEANS AND MOVABLE INTO ATLEAST ONE OF THE OPENINGS OF SAID MOLD, MEANS FOR MOVEMENT OF SAIDSENSING AND GAUGING IN GENERALLY VERTICAL DIRECTIONS, SAID GAUGING MEANSBEING MOVABLE TO SAID EXTERNAL ELEMENT TO LIMIT THE EXTENT TO WHICH SAIDSENSING MEANS ENTERS INTO SAID OPENINGS, AND MEANS OPERATIVE FORCONTROLLING SAID CASTING OPERATION UPON CONTACT OF MOLTEN METAL WITHSAID SENSING MEANS.